| Discovery | |
|---|---|
| Discovered by | Khandelwal et al.[1] |
| Discovery site |  India |
| Discovery date | 2023 |
| Transit | |
| Orbital characteristics | |
| 0.0888±0.001 AU[2] | |
| Eccentricity | 0.325±0.02[2] |
| 7.246[2]d | |
| Inclination | 80.21°[2] |
| Star | HD 245134 (TOI-4603) |
| Physical characteristics | |
| 1.042+0.035 −0.038 RJ[2] | |
| Mass | 12.89+0.57 −0.58 MJ[2] |
Meandensity | 14.1+1.6 −1.7 g/cm3[2] |
| Temperature | 1,677±24 K (1404 °C)[2] |
TOI-4603 b is agas giant exoplanet orbiting HD 245134, aF-typesubgiant star located 731light-years away, in the constellation ofTaurus.[3][note 1] It orbits its host star at a distance of 0.0888 astronomical units (13,280,000 km), completing one orbit every 7 days around it.[2] With a density of 14.1g/cm3 (about 2.5 times that of Earth), it is one of the densest exoplanets known.[2] The planet is just 4% larger thanJupiter, but is 12.9 times more massive, being located in the mass limit between planets andbrown dwarfs.[2]
TOI-4603 b is similar to the planetJupiter in size, being only 4% larger.[2]Radial velocity measurements calculated the planet's mass to be12.89+0.58
−0.57 MJ[4] meaning that the object is close to the mass limit between planets andbrown dwarfs, which is usually set at13 MJ.[2] Itsequilibrium temperature is calculated at 1,677 K (1,404 °C).[2]
Combining the radius and mass, the density of TOI-4603 b is calculated to be14.1+1.6
−1.7g/cm³, about 2.5 times greater than Earth's,[note 2] making it one of the densest exoplanets known to date, and one of the most massive and densetransiting exoplanets known.[2]
TOI-4603 b orbits its star at a distance of 0.0888 astronomical units (13,280,000 km), and completes one orbit every 7 days and 6 hours.[2] The orbit of TOI-4603 b is very elliptical, having anorbital eccentricity of 0.325, which indicates that the planet is undergoingtidal migration due to agravitational interaction with another planet.[2] Kervella et al. (2019) found that abrown dwarf with a mass of20.5 MJ is orbiting the system at a distance of around 1.8AU, which may be influencing TOI-4603 b's orbit.[2]
A similar object is a planet calledHATS-70b. It is less dense than TOI-4603 b, but similarly close to its star, and also shows signs oforbital migration.[4]
NASA'sTransiting Exoplanet Survey Satellite observed the host star TOI-4603 between September 16, 2021, and December 2, 2021.[2] Afterwards, the group of astronomers led by Akanksha Khandelwal of thePhysical Research Laboratory (PRL) in India, reported that atransit signal had been identified in the light curve of the star.Radial velocity measurements taken with thePARAS andTRES[note 3]spectrographs confirmed the transit signal to be an exoplanet orbiting the star.[6]
It was the third exoplanet discovered by Indian astronomers, using thePARAS spectrograph and thePRL 1.2 mtelescope.[7] The discovery was announced in 2023.[8]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Taurus[note 1] |
| Right ascension | 05h 35m 27.82281s[9] |
| Declination | +21° 17′ 39.6246″[9] |
| Apparent magnitude (V) | 9.2[2] |
| Characteristics | |
| Evolutionary stage | Subgiant |
| Spectral type | F |
| Astrometry | |
| Radial velocity (Rv) | -3.29[10] km/s |
| Proper motion (μ) | RA: +0.102mas/yr[9] Dec.: −22.866mas/yr[9] |
| Parallax (π) | 4.4613±0.0195 mas[9] |
| Distance | 735.596+8.098 −7.928 ly (225.643+2.484 −2.432 pc)[1] |
| Details[2] | |
| Mass | 1.765±0.061 M☉ |
| Radius | 2.738+0.061 −0.050 R☉ |
| Luminosity | 10.4 L☉ |
| Surface gravity (log g) | 3.94±0.1 cgs |
| Temperature | 6,264+95 −94 K |
| Metallicity [Fe/H] | 0.342+0.039 −0.040 dex |
| Rotational velocity (v sin i) | 23.18±0.37 km/s |
| Age | 1.64+0.30 −0.24 Gyr |
| Other designations | |
| TOI-4603,2MASS J05352782+2117396, AG+21 537, AGKR 4971,BD+21 897,Gaia DR1 3402980516507429888,Gaia DR2 3402980516507429888,Gaia DR3 3402980516507429888,GSC 01309-01102, HIC 26250,HIP 26250,PPM 94530,SAO 77288,TIC 437856897,TYC 1309-1102-1, YZ 21 1805 | |
| Database references | |
| SIMBAD | data |
HD 245134 (TOI-4603) is aF-typesubgiant located 736light-years away in the constellation ofTaurus.[1][note 1] It is well suited for the study of theRossiter–McLaughlin effect and helpful for measuring the projected stellar obliquity of planets.[2] The star has anapparent magnitude of 9.2, being too faint to be seen with the naked eye.[1] It is ametal-rich star, with abundance of iron 2.2 times greater than that of the Sun.[2]
HD 245134 is orbited by an exoplanet (TOI-4603 b), and by a20.5 MJbrown dwarf star at a distance of 1.8AU from the star.[2]
